The present invention relates to a new and improved construction of containers or receptacles, hereinafter broadly referred to as cans formed of thin-walled material, particularly of sheet steel or sheet aluminum and comprising a can body containing beads formed therein. The present invention also relates to a new and improved construction of apparatus for producing fine precision beads in thin-walled cans or the like fabricated from sheet material or plating.
It is known to form circumferential beads in the body of cans, particularly thin-walled cans formed from sheet material.
The beads serve to increase the strength of the can in axial and/or in radial direction. Circumferential beads increase the collapse strength when the cans are evacuated or are subjected to cooking processes in an autoclave. Such circumferential beads are presently extensively applied to foodstuff-containing cans.
In containers, particularly large size containers having a volume of 200 liters as known, for example, from British Pat. No. 973,373 and British Pat. No. 978,982, the circumferential beads extend at an inclination relative to the horizontal or along a helical line. Such circumferential beads result in satisfactory strength of the cans in respect of their collapse, however, the axial strength thereof is reduced to an intolerable extent by virtue of the deformation of the can body. Thus it will occur with increasing frequency that containers or cans of such construction when stacked to large heights in a store or other location may fold or buckle under the load of the overlying cans. Thus entire stacks of such containers or cans, which may extend to a height of several meters, can tumble.
In another state-of-the-art container as known, for example, from German Utility Model No. 8,024,406, horizontally positioned assemblies or groups of beads have therefore been suggested and between which there are located planar, non-deformed wall areas which are supposed to contribute to an increase in the axial strength.
Furthermore, in another container construction having circumferential beads as taught, for example, by German Patent Publication No. 3,001,787 there are provided short, vertically extending bead sections which are arranged in juxtaposition, however, offset from each other and which interrupt the circumferential beads.
Another container design as known, for example, from Belgian Pat. No. 411,724, only has a small number of horizontal beads which are spaced far from each other and which are strongly embossed and vertical beads which are likewise spaced far from each other but which are less strongly embossed. Planar, non-deformed body areas or regions are located between the vertical and horizontal beads.
While the axial strength may be actually increased by means of the vertically positioned beads or bead sections, such increase, however, is gained at the expense of the collapse strength.